Yeah, i did that with my commander bly about 6 months ago. In Sydney we have what you have probably heard of as the "city to surf" which is 14.5kms long, and i knew i would not make it in full clone gear without hydration. So i got a 1L camel pack, some elastic strips and combined them. If anyone here has clone gear, you'd know that the backplate has that hollow recess in it. so what i did was put the bladder in there. Once it had filled up that recess, i put three strips of elastic horizontally over it, and it held it in there while i was trooping/running. Best part was i had kept it in the freezer at near freezing temperatures, so it kept my back nice and cool for the first half of the run (even though all i could manage was a moderate jog...)
hope this helps guys
